This invention relates generally to the field of image displays, and more particularly to a system and method for displaying an image using display distortion correction.
Although video and other image display surfaces, such as projection screens, are often substantially flat, certain applications call for non-flat display surfaces. One example is a concave display surface, such as might be associated with a computer monitor or a domed theatre. Since video and other image display equipment typically generates an image signal assuming a substantially flat display surface, distortion is created if such an image is displayed on a curved, irregular, or other non-flat surface. Therefore, there is a need to correct for this distortion when an image is to be displayed on a non-flat display surface. Previous methods of correcting for display distortion have included optical devices (such as lenses), texture mapping hardware, and polynomial warping hardware. These techniques are often relatively expensive and are typically limited to a limited number of pre-defined display surfaces. The texture mapping and polynomial warping hardware in particular require significant computer resources and may decrease the ability of the image display equipment to generate the image efficiently.
According to the present invention, disadvantages and problems associated with previous systems and methods for displaying images have been substantially reduced or eliminated.
A system for display distortion correction includes a database that stores one or more pixel correction vectors and one or more sub-pixel correction vectors. The system also includes a buffer that receives and stores an input image data unit including a plurality of pixels. Furthermore, the system includes a system controller that is coupled to the database and to the buffer. The system controller generates a coarsely-corrected image data unit including a plurality of pixels by mapping one or more pixels of the coarsely-corrected image data unit to corresponding pixels of the input image data unit according to corresponding pixel correction vectors. Each pixel correction vector is associated with a particular pixel of the coarsely-corrected image data unit. The system also includes an interpolation filter that is coupled to the system controller and the database. The interpolation filter receives the coarsely-corrected image data unit and generates a finely-corrected image data unit using the coarsely-corrected image data unit and corresponding sub-pixel correction vectors.
The system and method of the present invention provide a number of important technical advantages. The present invention is less expensive more computationally efficient, and more versatile than existing techniques for display distortion correction. The present invention accomplishes display distortion correction using correction vectors that have been previously calculated to map pixels of an uncorrected video or other suitable input image to pixels of a corrected video or other output image. The correction vectors may be determined for virtually any specified display surface using conventional techniques. Because only one set of correction vectors is required for each specified display surface, these vectors can be calculated once and the results stored for multiple subsequent uses according to the present invention. Existing display distortion correction techniques require a non-flat surface to flat surface mapping to be performed for every video frame or other unit of image data, which often requires substantial computer resources. In addition, the performance of these systems varies based on the type of display surface to be used (processing more complicated and irregular display surfaces typically takes longer). Other existing systems using relatively expensive optical equipment, such as optical lenses, are typically limited to a relatively small number of pre-defined display surfaces. The present invention, in contrast, provides a relatively inexpensive, efficient, and universal method of correcting display distortion. Other important technical advantages are readily apparent to those skilled in the art.